Aerofoil for a turbine blade

Patent metadata

Field	Value
Publication number	US-11326458-B2
Application number	US-201917048582-A
Country	US
Kind code	B2
Filing date	May 3, 2019
Priority date	May 4, 2018
Publication date	May 10, 2022
Grant date	May 10, 2022

Abstract

An aerofoil for a turbine blade, having a leading edge onto which a hot gas can flow and from which a suction-side wall and a pressure-side wall extend to a trailing edge of the aerofoil, the aerofoil extending in a direction transverse thereto from a root-side end having an aerofoil height of 0% to a tip-side end having an aerofoil height of 100%, and having at least two rows of cooling holes arranged along the leading edge, which cooling holes are at a mutual spacing which can be measured perpendicularly to the leading edge. In order to provide a turbine blade which can be used, with reduced cooling complexity, for additional reliable cooling of the leading edge in various operating conditions, the at least two rows of cooling holes are arranged at least in part in a wavy line along the leading edge.

First claim

The invention claimed is:

1. A hollow airfoil for a turbine blade, comprising:
a leading edge against which a hot gas is able to flow and from which a suction-side wall and a pressure-side wall extend to a trailing edge of the airfoil, wherein, in a transverse direction with respect thereto, the airfoil extends from a root-side end at an airfoil height of 0% to a tip-side end at an airfoil height of 100%,
at least two series of cooling holes that are arranged along the leading edge, which, with respect to one another, have a first spacing which is to be measured perpendicularly to the leading edge,
wherein the at least two series of cooling holes are arranged at least partially on a wavy line along the leading edge, and
wherein a blade profile is able to be determined for any airfoil height, which blade profile has a nose radius in a region of the leading edge, wherein, at the height of cooling holes, the blade profiles have between the at least two series a first spacing whose size lies in the range between 0.4 and 0.7 times the associated nose radius.

2. The airfoil as claimed in claim 1 ,
wherein the at least two series of cooling holes are arranged on a wavy line along an entire extent of the leading edge between 0% and 100% airfoil height.

3. The airfoil as claimed in claim 1 ,
wherein the at least two series of cooling holes are arranged only partially on a wavy line along the leading edge, such that the at least two series of cooling holes are, in a first region, which is arranged between 0% and approximately 40% airfoil height, arranged on both sides of the leading edge in a substantially parallel manner and, in a second region, which directly adjoins said first region and extends between approximately 40% and approximately 75% airfoil height, arranged so as to be shifted to the pressure side, and wherein the at least two series of cooling holes are, in a third region, which directly adjoins the second region and ends at 100% airfoil height, arranged so as to be shifted back further toward the leading edge with increasing airfoil height.

4. The airfoil as claimed in claim 3 ,
wherein, from an airfoil height of 40%, the at least two series of cooling holes are displaced to the pressure side such that a point of maximum displacement on the pressure side is arranged at approximately 75% airfoil height or higher.

5. The airfoil as claimed in claim 4 ,
wherein the maximum displacement on the pressure side is from 2% to 10% of a blade chord length, which corresponds to an axial spacing between the leading edge and the trailing edge, measured at the airfoil height of the maximum displacement.

6. The airfoil as claimed in claim 1 ,
wherein the first spacing between the at least two series varies along the leading edge.

7. The airfoil as claimed in claim 1 ,
wherein the first spacing, at an airfoil mid-height, is at its smallest and increases toward the two ends.

8. The airfoil as claimed in claim 1 ,
wherein each cooling hole has a throttle cross section which sets a cooling medium throughflow, wherein the throttle cross sections of some cooling holes are of different sizes.

9. The airfoil as claimed in claim 8 ,
wherein the throttle cross sections of the cooling holes in the region of an airfoil mid-height are larger than the throttle cross section of the cooling holes in the region further away from the airfoil mid-height.

10. The airfoil as claimed in claim 1 ,
wherein the at least two series of cooling holes are arranged on both sides of a stagnation point line of an incoming hot-gas flow.

11. The airfoil as claimed in claim 1 ,
wherein the wavy line, without a change in sign of its curvature, is slightly curved in such a way that, both at the root-side end and at the tip-side end of the airfoil, the cooling holes of each of the at least two series are arranged further to the suction side than the cooling holes of the corresponding series at an airfoil mid-height.

12. The airfoil as claimed in claim 11 ,
wherein, beside the at least two series, a further series of cooling holes is provided adjacently on the pressure side, wherein a length of the further series is between 50% and 60% of the airfoil height, and the further series is arranged substantially centrally between the two ends of the airfoil.

13. A turbine blade for a stationary gas turbine, comprising:
an airfoil as claimed in claim 1 .

14. The turbine blade of claim 13 ,
wherein the turbine blade comprises a turbine guide blade.

15. An airfoil for a turbine blade, comprising:
a leading edge against which a hot gas is able to flow and from which a suction-side wall and a pressure-side wall extend to a trailing edge of the airfoil, wherein, in a transverse direction with respect thereto, the airfoil extends from a root-side end at an airfoil height of 0% to a tip-side end at an airfoil height of 100%,
at least two series of cooling holes that are arranged along the leading edge, which, with respect to one another, have a first spacing which is to be measured perpendicularly to the leading edge,
wherein the at least two series of cooling holes are arranged at least partially on a wavy line along the leading edge,
wherein each cooling hole has a throttle cross section which sets a cooling medium throughflow, wherein the throttle cross sections of some cooling holes are of different sizes, and
wherein the throttle cross sections of the cooling holes in the region of an airfoil mid-height are larger than the throttle cross section of the cooling holes in the region further away from the airfoil mid-height.

16. An airfoil for a turbine blade, comprising:
a leading edge against which a hot gas is able to flow and from which a suction-side wall and a pressure-side wall extend to a trailing edge of the airfoil, wherein, in a transverse direction with respect thereto, the airfoil extends from a root-side end at an airfoil height of 0% to a tip-side end at an airfoil height of 100%,
at least two series of cooling holes that are arranged along the leading edge, which, with respect to one another, have a first spacing which is to be measured perpendicularly to the leading edge,
wherein the at least two series of cooling holes are arranged at least partially on a wavy line along the leading edge, and
wherein the wavy line, without a change in sign of its curvature, is slightly curved in such a way that, both at the root-side end and at the tip-side end of the airfoil, the cooling holes of each of the at least two series are arranged further to the suction side than the cooling holes of the corresponding series at an airfoil mid-height.

Assignees

• Siemens Energy Global Gmbh & Co Kg

Inventors

• Ahmad Fathi
• Koch Daniela
• Schüler Marco

Classifications

• F01D5/186 Primary

  Film cooling (F01D5/187 takes precedence) · CPC title

• F05D2220/32

  in gas turbines · CPC title

• F05D2260/202

  by film cooling · CPC title

• F05D2240/303

  related to the leading edge of a rotor blade · CPC title